JPS63180921A - Method and device for manufacturing spacer for carrying optical fiber - Google Patents

Abstract

PURPOSE:To eliminate the need for heating facilities by cooling and caking resin after a shaping plate which corresponds to the groove shape of a spiral groove and rotate synchronously with a rotary die and also independently abuts on the spiral groove while the resin is in a soft state. CONSTITUTION:The distance between the rotary die and shaping plate 38 is made constant and an internal rotary base 32 is allowed to rotate independently of an external rotary base 24 which rotates in synchronism with the rotary die. Namely, when the distance between the rotary die and shaping plate 38 is made constant, the spiral groove has a phase difference between the part right after the discharging of the rotary die and the part where the shaping plate 38 abuts on a spacer, and the part corresponding to the phase difference is absorbed by rotating the internal rotary base 32 independently. Therefore, when the spiral groove reaches the shaping plate 38, the internal rotary base 32 rotates and begins to rate almost in synchronism with the external rotary base 24 and the internal and external rotary bases 24 and 32 are coupled by a screw 46, thereby manufacturing the spacer while rotating them completely in synchronism. Consequently, the manufacture is performed before the resin is caked, so the need for heating facilities is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for manufacturing a spacer with a spiral groove used as an element of an optical fiber cable.

Regarding the device, in particular, we would like to provide a manufacturing method and device that can obtain a spacer with a spiral groove having good shape accuracy.

(Prior art and its problems) When converging optical fibers for optical communication into a cable, a spacer with multiple continuous spiral grooves on the outer periphery is used, and the optical fibers are housed within these grooves. carried.

As a manufacturing method for this type of optical fiber supporting spacer,
A method in which molten resin is extruded around the outer periphery of a tensile strength wire such as a single or twisted steel wire through a rotating die, a recess corresponding to the spiral groove is provided in the rotating die, and the resin coating and the spiral groove are simultaneously formed. There is.

However, with this method, the ribs may become tilted or twisted due to extrusion of the resin while rotating, and an imbalance in the cooling rate between the grooves and the ribs that form the spiral grooves. In many cases, there is the problem that uniform groove width and depth cannot be ensured, and this has been dealt with by measures such as slowing down the molding speed as much as possible.

In particular, recently, in order to store more optical fibers, a method has been adopted in which ribbon-shaped optical fiber units, which are multiple optical fibers arranged in parallel, are stored in a stacked state in the rectangular groove of a spacer. Now, the highest level of precision in groove shape is required.

By the way, as a manufacturing method for obtaining good shape accuracy of the groove portion, for example, Japanese Patent Application Laid-Open No. 58-126504 or Japanese Patent Application Laid-Open No. 58-126505 has been disclosed.

The method disclosed in these publications involves extruding the resin around the outer periphery of the core material while rotating a die, forming a spiral groove, cooling and solidifying the resin, and then inserting the resin into a pressure die and a cutting die having through-holes. The latter is a method in which the material is once cooled and solidified and then heated and brought into contact with a plurality of rollers having circumferential steps and a drawing hole to form a predetermined shape, each of which is explained below. There was a problem.

That is, in the former method, the shape is formed using a cutting die in a solidified state, so if the cutting die does not cut well, excessive force is applied to the spacer, which may damage the adhesion between the tensile strength wire and the resin forming the spacer. , there was a risk that the resin would be stretched.

In addition, in the latter method, the spacer, which has been cooled and solidified, is heated again to soften it, which requires a new heating means, which poses a problem in terms of equipment costs and energy costs.

Therefore, the present inventors extruded a synthetic resin in a molten state around the outer periphery of a core material such as a tensile strength wire to produce a spacer having a spiral groove. The present invention was developed after intensive study to solve the problems such as the need for heating equipment for molding after cooling. An object of the present invention is to provide a method and apparatus for manufacturing a spacer for supporting an optical fiber.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an optical fiber support having a thermoplastic resin coating layer on the outer periphery and forming a continuous spiral groove in the coating layer. In the method for manufacturing a spacer, after the resin is melted and extruded from a rotating die to form the spiral groove, the resin is melted and extruded from a rotating die, and then the resin is melted and extruded from a rotating die. The manufacturing method is characterized in that a rotatable shaping plate is brought into contact with the spiral groove while the resin is in a softened state, and then the resin is cooled and solidified. In an apparatus for manufacturing an optical fiber supporting spacer that forms a continuous spiral groove (in a coating layer), a rotating die that discharges the resin in a molten state, an outer rotating base that rotates in synchronization with the rotating die, and an outer rotating base that rotates in synchronization with the rotating die; an inner rotating base rotatably attached to the die and rotatable in synchronization with the rotating die;
The manufacturing device comprises a shaping plate supported by the inner rotating base so as to be movable in a central direction, and having a resin in a softened state in contact with the spiral groove discharged from the rotating die, and having a cross section corresponding to the groove shape. The characteristics of

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 and 2 show an embodiment of the method and apparatus for manufacturing an optical fiber supporting spacer according to the present invention.

The method shown in the figure includes an extruder 10 that extrudes and coats the outer periphery of the tensile strength line with a molten thermoplastic resin, a spiral groove shaping device 20, and a cooling device 50 that cools and solidifies the thermoplastic resin.
is used.

The extrusion 11t10 is performed using a die head 12 formed to allow insertion of a tensile strength wire, and a die head 12 disposed at the tip of the die head 12 to form a plurality of spiral grooves continuous in the longitudinal direction on the outer periphery using the extruded synthetic resin at a predetermined pitch. A rotating die 14 is provided, and the synthetic resin for the spacer is extruded almost vertically downward through the mouthpiece of the rotating die 14.

Details of the shaping device 20 are shown in FIG. 2.

The shaping device 20 shown in the figure is a rotary die 1 of an extruder 10.
4, an outer rotating base 24 coupled to a connecting shaft 21, 21 and a rotating plate 221 via a rotating shaft 23, and a hollow cylindrical support block 28 disposed on the inner peripheral side of the outer rotating base 24 via a bearing 26. and support block 28
and an inner rotating base 32 disposed via a bearing 30 on the inner peripheral side.

A ring-shaped shaping plate holder 34 is mounted and fixed on the upper surface of the outer periphery flange portion 32a of the inner rotation base 32, and a plurality of holes bored in the circumferential direction of the holder 34 are provided with rotatable ronds 36. A disc-shaped shaping plate 38 supported by the inner rotary base 32 is inserted through each of them, and the shaping plate 38 can move forward and backward with respect to the center axis of the through hole 32b of the inner rotating base 32.

Further, by rotating the rod 36, the inclination angle of the shaping plate 38 can be changed in accordance with the pitch of the spiral groove, and this angle can be fixed with a screw (not shown).

The cross-sectional shape of each shaping plate 38 corresponds to the groove shape of the spiral groove of the spacer to be manufactured, and is set to a number corresponding to the number of threads of the spiral groove at a predetermined angular interval M.

Further, the depth of the groove formed by each shaping plate 38 is adjusted by adjustment plates 40 and 40 that respectively abut on the rear end of the rond 36 holding the shaping plate 38, and the adjustment plate 40 is attached to the holder 3 by means of a mounting screw 42. Fixed.

In addition, the above-mentioned shaping device 20 has inner and outer rotating bases 32 and 34.
support block 2 so that it is coaxial with the rotating die 14.
8 is supported by a mounting flange 44 fixedly provided below it.

Further, a screw 46 protruding from the outer peripheral flange 24a of the outer rotation base 24 connects the inner rotation base 32 and the outer rotation base 24.
It is intended to combine the following.

With the above configuration, the outer rotating base 24 can rotate the rotating shirt 1-
Rotates synchronously with the rotating die 14 via 23,
If the inner rotating base 32 is not connected with the screws 46, it can separate from the outer rotating base 24 and rotate independently, and if it is connected with the screws 46, it will rotate synchronously with the rotating die 14.

On the other hand, the cooling device 50 is provided coaxially below the shaping device 20, and includes a first cooling air nozzle 52 provided directly below the mounting flange 44, and a second cooling air nozzle 52 provided below this nozzle 52. Air nozzle 54 and nozzle 54
The cooling water tank 56 is provided below the cooling water tank 56.

Each cooling air nozzle 52 , 54 blows cooling air upward onto the surface of the spacer to cool it. In particular, the air discharged from the first cooling air nozzle 52 is directed toward the inner rotating base 32 of the shaping device 20 . While cooling the spacer discharged from the rotating die 14 through the through hole 23b and the shaping plate 38, 38, the inner rotating base 32
．． The shaping plate 38 is cooled.

The spacer A cooled and solidified in the cooling water tank 56 is moved to the water tank guide roller 58. It passes through a guide roller 60 and is wound up by a winding machine (not shown).

Note that a water receptacle 62 is provided below the water tank guide roller 58, and a draining air nozzle 64 is provided behind the guide roller 60.

Further, a member 66 shown in FIG. 1 is a windproof tube that is attached to the outer periphery of the connecting shaft 21 and prevents the spacer immediately after being discharged from the rotary die 14 from being affected by the outside air.

Now, in order to manufacture an optical fiber supporting spacer using the above-described apparatus, first, the resin is extruded without rotating the rotary die 14.

In this state, the outer rotating base 24 of the shaping device 20 does not rotate, and a linear groove is formed on the outer periphery of the spacer, so that the shaping plate supported by the inner rotating base 32 of the shaping bag @20 38 into each groove.

Next, when the rotating die 14 is rotated, a spiral groove is formed on the outer periphery of the spacer, and the outer rotating base 24 rotates synchronously with the rotating die 14, but the inner rotating base 32
does not rotate until the spiral groove portion reaches the shaping plate 38.

Here, when the inner rotary base 32 is rotated synchronously with the rotary die 14 in the same way as the outer rotary base 24, there is a time delay until parts of the same phase of the spiral groove discharged from the rotary die 14 reach the shaping plate 38. Because of this, twisting occurs in the spiral groove.

Further, various helical pitches of the spacer are required, but in this case, for example, unless the distance between the rotating die 14 and the shaping plate 38 is set to an integral multiple of the pitch of the helical groove, the above-mentioned problem will occur. Therefore, the distance must be adjusted for each pitch of the spiral groove.

Therefore, in the present invention, the distance between the rotating die 14 and the shaping plate 38 is kept constant, and the inner rotating base 32 is configured to be able to rotate independently of the outer rotating base 24 that rotates in synchronization with the rotating die 14. .

In other words, if the distance between the rotary die 14 and the shaping plate 38 is kept constant, the
A phase difference between the helical grooves and the portion where the groove contacts the spacer occurs, but the portion corresponding to this phase difference is absorbed by independently rotating the inner rotary base 32.

Therefore, when the spiral groove reaches the shaping plate 38, the inner rotating base 32 rotates, and when it begins to rotate almost synchronously with the outer rotating base 24, the inner and outer rotating bases 24 and 43 are connected by the screw 46, The spacer will be manufactured with completely synchronous rotation.

(Effects of the Invention) As described above in detail in the Examples, according to the method and apparatus for manufacturing an optical fiber supporting spacer according to the present invention, the shaping plate comes into contact with the softened resin, so that the abrasion and The degree of cutting is not a problem, and the shape can be reliably shaped and straightened, and heating equipment is not required since the process is performed before the resin is cooled and solidified.

[Brief explanation of the drawing]

Figure 1 is an overall explanatory diagram of the method and apparatus of the present invention, and Figure 2 is the first diagram.
It is an enlarged view of the main part of the figure. 14... Rotating die 20... Shaping device 24... External rotating base 32...
Inner rotation base 38... Shaping plate 50...
...Cooling device 1'? I Applicant Representative of Ube Nitto Kasei Co., Ltd. Patent attorney - Kensuke Shiro Patent attorney Masatoshi Matsumoto Figure 1

Claims (2)

[Claims] (1) In a method for manufacturing an optical fiber supporting spacer having a thermoplastic resin coating layer on the outer periphery and forming a continuous spiral groove in the coating layer, the resin is melted to form the spiral groove. After the resin is extruded from a rotating die, a shaping plate corresponding to the groove shape of the spiral groove and capable of rotating synchronously with the rotating die and independently rotating is brought into contact with the spiral groove while the resin is in a softened state. A method for manufacturing an optical fiber supporting spacer, comprising: cooling and solidifying the resin. (2) In an apparatus for manufacturing an optical fiber supporting spacer having a thermoplastic resin coating layer on the outer periphery and forming a continuous spiral groove in the coating layer, a rotating die for discharging the resin in a molten state; an outer rotating base that rotates in synchronization with the rotating die; an inner rotating base that is rotatably attached to the outer rotating die and capable of rotating in synchronization with the rotating die; 1. An apparatus for manufacturing an optical fiber supporting spacer, comprising a shaping plate in which a softened resin contacts a spiral groove discharged from a rotating die and has a cross section corresponding to the groove shape.